1. Field of the Invention
This invention relates generally to an IC memory card, and more particularly to an improvement of terminal joints of an IC memory card for use as an external storage medium of an electronic data processing machine.
2. Description of the Related Art
As is known in the art, when an IC memory card, in the form of a plastic card in which an IC memory is mounted, is inserted in an electronic data processing machine to be connected with a read/writer, the read/writer can read/write necessary data stored in the IC memory. For this reason, an IC memory card is usable for various kinds of electronic systems in which a large quantity of data, must be stored in a handy card.
Such IC memory card is usable in database, such as a bankbook, dictionary data or map data, and is particularly useful in settlement of bank accounts or for expansion memory of an electronic pocketbook. It is also usable as a program source of a computer, and is particularly useful as a simple external storage medium for a personal computer or a relatively large computer. However, in this kind of IC memory card, an electrical contact between the memory card and the read/writer is needed to read/write data; for this purpose, a durable inexpensive connector structure is required to realize a simple reliable connection.
Conventional connector structures are classified into two types: a card-edge type and a two-piece type.
In the card-edge type connector structure, a plurality of lead terminals are exposed to an end surface of the IC memory card. When the card is inserted into the read/writer, the exposed lead terminals are connected with the terminal strip on the read/writer side. Because its structure is simple and can be realized at a low cost, this connecting system has commonly been used, for example, in a game machine. But this conventional structure is poor in reliability and durability and cannot be used in a high-quality IC memory card.
In the two-piece type connector structure, a plurality of male terminal pins mounted on the read/writer can be coupled with a female terminal mounted on the IC memory card. Since the individual male and female terminals are interconnected with each other stably, a durable and reliable memory card can be obtained.
However, the conventional two-piece type connector structure requires a female connector on the IC memory card for every terminal. It is difficult to incorporate connectors, each in the form of such a metal spring, in a thin memory card.
Particularly for modern memory cards, a large number of terminal pins, such as 34 pins in a row and 68 pins in two rows, are required according to, for example, the JEIDA (Japan Electronic Industry Development Association) standard. Also from a view point of cost, it is short of reality to incorporate this complex connector structure in a memory card.